Edge Effect on Coercive Field of GMR Sensors with Meander Line Structure

Author

Chan, Y.H. ; Chen, M. ; Chiang, J.J. ; Liao, I.C. ; Wu, T.H. ; Lee, Chang Min ; Peng, W.Y. ; Chen, J.Y. ; Lai, J.Y. ; Lo, C.K. ; Wei, Z.H.

Author_Institution

Inst. of NanoEngineering & Microsyst., Nat. Tsing Hua Univ., Hsinchu, Taiwan

Volume

50

Issue

1

fYear

2014

fDate

Jan. 2014

Firstpage

1

Lastpage

4

Abstract

Edge effect plays a major role on magnetic properties in permalloy microstructures. To perform high dynamic range, the meander line has been used in giant magnetoresistance (GMR) sensor for increasing the sensor active area. In this paper, we fabricated GMR sensors with various edge structures by using a photolithography and e-beam evaporation system. The device properties are measured by magnetoresistance (MR) system and compared with Object Oriented MicroMagnetic Framework (OOMMF) simulations. Magnetic moment and domain states were analyzed with respect to the edge shapes. The round corners reveal more the formation of magnetic vortex which means lowered magnetostatic energy in the GMR sensor. We found out that by altering the geometry of the edges on the GMR sensors, we can control the coercive field. When the edge structure is circular rather than rectangular, the coercive field is respectively found to be 37.5 Oe rather than 57.5 Oe, yielding a 15% variation rate by utilizing this edge effect.

Keywords

Permalloy; coercive force; electron beam applications; giant magnetoresistance; magnetic domains; magnetic moments; magnetic sensors; magnetoresistive devices; micromagnetics; photolithography; GMR sensors; NiFe; Permalloy microstructures; coercive field; e-beam evaporation; edge effect; magnetic domain states; magnetic moment; magnetic properties; magnetic vortex formation; magnetoresistance system; magnetostatic energy; meander line structure; object oriented micromagnetic framework simulations; photolithography; round corners; Magnetic domain walls; Magnetic domains; Magnetic resonance imaging; Magnetic sensors; Perpendicular magnetic anisotropy; Coercive field; edge effect; giant magnetoresistance (GMR);

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2013.2273453

Filename

6693027